117.5 was often sold for a 130mm hub.....hence 5mm shorter. 130 and 135 hubs were still included in the m732 line up. But the logic doesn't exactly follow, as you may need to watch the frame geometry with bigger insde rings. But it did give a theoretical better chain line.
Original 122.5 axles are asymmetric...the more modern 122 ones are not (most of the time). However the difference is 1mm each way.
I use both cup amd cone 122.5 and 122 sealed. The difference is not noticeable in terms of chain movement or run.
You do see the difference if you really look hard (sometimes) (with a pair of calipers) at the spacing between crank arm and chain stay, but its not that close to ever be an issue.
1st pic is m730 chainset on 122.5 asymmetric cup and cone. 2nd is same on 122 symmetric sealed modern bb. Bugger all difference in reality.
Tbh the other factor is how worn the tapers are in the crank. A slightly worn or previously gorilla fitted crank can easily slip onto the taper by 2mm more anyway.
So the the bb exact size then becomes a fairly moot point when we are talking 1 or 2mm!
all the best with the build.
Original 122.5 axles are asymmetric...the more modern 122 ones are not (most of the time). However the difference is 1mm each way.
I use both cup amd cone 122.5 and 122 sealed. The difference is not noticeable in terms of chain movement or run.
You do see the difference if you really look hard (sometimes) (with a pair of calipers) at the spacing between crank arm and chain stay, but its not that close to ever be an issue.
1st pic is m730 chainset on 122.5 asymmetric cup and cone. 2nd is same on 122 symmetric sealed modern bb. Bugger all difference in reality.
Tbh the other factor is how worn the tapers are in the crank. A slightly worn or previously gorilla fitted crank can easily slip onto the taper by 2mm more anyway.
So the the bb exact size then becomes a fairly moot point when we are talking 1 or 2mm!
all the best with the build.
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